Paradigm shift of respiratory viruses causing lower respiratory tract infection in children during COVID-19 pandemic in India.

INTRODUCTION

Acute lower respiratory tract infections (ALRTIs) are the commonest cause of mortality in children mostly attributed to respiratory viruses. During the coronavirus disease 2019 (COVID-19) pandemic, the dynamics and transmission of infections changed worldwide due to widespread public health measures. This study aimed to understand the pattern of respiratory viruses associated with ALRTIs in children pre and during COVID-19 pandemic in India.

METHODOLOGY: Respiratory samples were collected from ALRTI patients during pre-pandemic period (October 2019 to February 2020; n = 166), Delta (July 2021 to December 2021; n = 78) and Omicron wave (January 2022 to July 2022; n = 111). Samples were screened for Influenza (Inf) A pdmH1N1, InfA H3N2, InfB, respiratory syncytial virus (RSV), human metapneumovirus (hMPV), human bocavirus (hBoV), human rhinovirus (hRV), and parainfluenza virus (PIV-2 and PIV-3) by nucleic acid amplification techniques (NAATs).

RESULTS

Significantly higher proportion of children with ALRTIs had virus/es isolated during pre-pandemic period than during mid-pandemic period [78.9% (131/166) vs. 52.9% (100/189); p < 0.001). RSV positivity was significantly higher (51.2%) in pre-pandemic period than 10.3% and 0.9% during the Delta and Omicron waves respectively. No significant difference in positivity rate of Inf A pdmH1N1, Inf A H3N2 and Inf B was seen. The increase in positivity of hRV (39.2% vs 42.3% vs 56.8%) and hBOV (1.2% vs 5.1% vs 9%) was documented in pre-pandemic, delta wave and omicron wave respectively.

CONCLUSIONS

The COVID-19 pandemic significantly impacted the frequency and pattern of respiratory viruses among hospitalized children with ALRTIs in India.